Several answers to your problem,
Firstly if you are worried about people copying the data and data
structures, then a database password is the simple way forward (not totally
secure but will stop the casual wanabe hacker). If you are worried about
your screen designs being used by others well compiling your MDB to MDE will
stop MOST people from ripping your designs, this will stop them from getting
to your code, as all human readable code is removed during compilation for
forms,modules, this route has the least amount of work for you to do.
When you use the word Application I guess you are referring to your Access
database not requiring Access to run, well 2 things here, using the Access
Runtime (Separate product from Microsoft, called Office Developer
Extensions), the removes the design time experience from Access so the
database performs much more like a normal application. Last option, use
Access just to store the data and write the front-end in another product
like vb etc, this does not stop a thief from stealing your creation but
makes it a big more difficult. Sadly if you want to have a product that is
very hard to steal your intellectual property, you will have to write a
proprietary database format and spend more time stopping people stealing it
rather than making a functional application.
So in summary if you want to make life harder for the 'drive by hacker'
compile your MDB to MDE, quickest win, less than 5 minutes to do and it will
stop 99% of them.